Half to jacob b



(No Model.)

I. O. GALLAI-IAN.

I ELEGTRIGA LLY GONTROLLBD TRAP DOOR.

No. 471,947. Patented Mar. 29, 1892.

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ATENT FFICE.

FRANK C. CALLAHAN, OF BRIDGEPORT, CONNECTICUT, ASSIGNOR OF ONE- HALF TO JACOB B; KLEIN, OF SAME PLACE.

ELECTRlCALLY-CONTROLLED TRAP-DOOR.

SPECIFICATION forming part of Letters Patent No. 471,947, dated March 29, 1892.

Application filed December 14, 1891. Serial No. 415,029- (No model.)

To all whom it may concern.-

Be it known that I, FRANK C. CALLAHAN, a citizen of the United States, residing at Bridgeport, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Electrically- Controlled Trap-Doors; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to certain new and useful improvements in electrically-controlled trap-doors, but more especially has reference I 5 to such doors as applied to the man-hole in a fire-engine house.

In all fire-engine houses where the sleeping-apartments for the firemen are located in an upper story there are one or more manholes in the floor of such apartment, and a slide-pole extends down through each of said holes to the ground-floor, the object of such arrangement being to afford a means whereby the firemen may descend to the ground-floor in the quickest possible amount of time. Many casualties have happened and are very liable to happen owing to the accidental falls through the unprotected man-holes, and it has been deemed inadvisable to close the lat- 3o ter by covers or doors which had to be opened manually, owing to the fact that the delay in opening the doors, especially 1n the event of excitement and confusion, was not only annoying, but was fatal to prompt and efficient service.

My invention contemplates the use of trapdoors to close the man-holes; but such doors are automatically opened simultaneous with the first stroke of the fire-alarm.

In order that those skilled in the art to which my invention appertains may fully understand the same, I will proceed to describe it in detail, referring by letter to the accompanying drawing, forming a part of this specification, and which shows n perspective a man-hole equipped with my improvement.- a. is the fioor, b the man-hole, and c the slide-pole.

d are trap-doors hinged at e to the floor and adapted when closed to cover the hole b.

f are L-shaped levers pivoted within the floor, and g are coil-springs around the pivots and having an effective action tending to throw said lever upward. At the outer ends of these levers are friction-rolls h, which have a constact bearing against the doors. It will thus be readily understood that the action of the levers f will tend to keep the doors open.

' i are electro-magnets within the floor, and

j are armatures carried by the doors, said armatures being so located that they will be in contact with the poles of the magnets when the doors are closed. The magnets are in circuit with the alarm, the latter bein g sounded by breaking the circuit.

The operation of my improvement is as follows: The doors being closed, the attraction of the armatures by the magnets will keep said doors closed against the resiliencyof the levers. When an alarm is sounded, the cir- 7o cuit will be broken. The magnets will thereby be deprived of vitality, andthe doors will be thrown open by the action of the levers.

I have shown my preferred manner of equipping the doors, so that they will open automatically by the action of a spring; but an, ordinary spring-hinge will answer the purpose, and, moreover, there are many ways of adapting a spring element so that it will effeet the automatic opening of the doors, all of which ways are very ordinary and within the scope of mechanical skill. I do not therefore wish to be limited to the use of any particular spring device in this connection; also, in case sliding doors are used which open automatically by the action of a spring the position of the armatures and magnets are simply changed, so that the effective action of the magnets may best overcome the force exerted by the spring element.

I claim- 1. The combination of the doors, a spring device for automatically opening them, armatures carried by said doors, and electro-magnets which attract said armatures and there- 5 by maintain the closed position of the doors against the resiliency of the spring element, substantially as shown and set forth.

2. In a device of the character described, the combination of the resiliently-acting doors roe the spring element while the magnets themselves are in circuit with the fire-alarm,where by when the circuit is broken to sound an alarm the magnets Will lose their Vitality and the spring element will throw open the doors, substantially as shown and set forth.

In testimony whereof I aflix my signature in presence of two witnesses.

FRANK G. CALLAHAN.

Witnesses:

J. S. FINCH, F. W. SMITH, Jr. 

